People who used both tobacco and cannabis products were more likely to screen positive for depression than users of either alone | Research

The takeaway

Among over 5,000 Americans aged 13-40, co-use of tobacco and cannabis products in the past 30 days was associated with 32% higher depression odds than tobacco alone and 94% higher than cannabis alone, with e-cigarettes and smoked cannabis being the most common combination among those screening positive.

Mental health screeners and school counselors; tobacco cessation programs considering cannabis co-use.

94% higher depression odds in co-users vs cannabis-only users

What the researchers found

Co-use of tobacco and cannabis was associated with higher odds of depression screening positive compared to tobacco-only (aOR 1.32) and cannabis-only (aOR 1.94) use. Among specific products, e-cigarette use (aOR 1.56), cigarette use (aOR 1.24), and chewing tobacco (aOR 1.91) were individually associated with depression. The most common two-product combination among depression-positive individuals was nicotine e-cigarettes and smoked cannabis (27.6%).

Why it matters

By examining specific product combinations, this study reveals that the e-cigarette plus smoked cannabis pairing is the dominant pattern among depressed co-users, providing a concrete target for screening and intervention efforts.

The numbers in context

5,281 respondents with complete data. 1,803 (34.1%) reported co-use. Co-use vs tobacco-only: aOR 1.32 (95% CI 1.06-1.65). Co-use vs cannabis-only: aOR 1.94 (95% CI 1.28-2.94). E-cigarettes: aOR 1.56. Most common combo among depressed: e-cigs + smoked cannabis (27.6%, 614 people).

How the study worked

Cross-sectional online survey of a national convenience sample of 6,038 people aged 13-40. Depression screening and past 30-day use of 11 specific tobacco and cannabis products assessed. Analyses stratified by age group.

What this study cannot tell us

Cross-sectional design cannot determine if co-use causes depression or depressed individuals gravitate toward co-use. Convenience sample. Self-reported product use and depression screening (not clinical diagnosis). Cannot control for all confounders.

How to read the evidence

Large convenience sample with specific product analysis, but cross-sectional design and self-report limit causal inference.

When this study was published

2024 study

The bigger picture

The specific product-level analysis suggests that the mode of consumption matters. E-cigarettes and smoked cannabis share an inhalation delivery method that may create compound respiratory and neurochemical effects beyond what either product alone produces.

Questions still open

Does the e-cigarette plus cannabis combination have synergistic neurochemical effects that increase depression risk? Would treating nicotine dependence also improve cannabis outcomes?

Common questions

What counts as co-use?

Using at least one tobacco product and at least one cannabis product within the past 30 days. This could include different delivery methods like e-cigarettes, smoked cannabis, edibles, or blunts.

Does cannabis cause depression?

This study shows an association, not causation. People who are depressed may be more likely to use substances, and the combination of tobacco and cannabis use may be a marker for underlying risk factors rather than a direct cause.

Read the original research

Depression screening outcomes among adolescents, young adults, and adults reporting past 30-day tobacco and cannabis use.

Addictive behaviors, 156, 108076

View on PubMed ↗Publisher’s paper ↗

Citation

Gaiha, Shivani Mathur; Wang, Maggie; Baiocchi, Mike; Halpern-Felsher, Bonnie. (2024). Depression screening outcomes among adolescents, young adults, and adults reporting past 30-day tobacco and cannabis use.. Addictive behaviors, 156, 108076. https://doi.org/10.1016/j.addbeh.2024.108076